This summer it was Casemiro, two summers earlier it was Daniel Carvajal and two before that it was Jose Callejon. In the not-too-distant future, it could be Alvaro Morata as well. Evidently, Real Madrid quite like a buy-back clause.
The latest man to return to the Santiago Bernabeu in such circumstances, however, is the far lesser-known Lucas Vazquez.
Now 24, Vazquez is a product of Real Madrid's youth academy, having joined the club in 2007 as a 16-year-old. Part of Carlo Ancelotti's squad that toured the United States for last summer's pre-season campaign, the winger was then sent to Catalonia and spent the 2014-15 season on loan with Espanyol. In that deal, Real Madrid got exactly what they wanted: significant playing time for the forward and a negligible buy-back option of €1 million that they've now exercised.
Under Sergio Gonzalez at the Estadi Cornella-El Prat, Vazquez enjoyed the sort of prominence he needed, starting 31 of Espanyol's 38 league games as a hard-working right-winger. In total, he scored four goals and tallied six assists in all competitions and finished eighth in La Liga for successful dribbles with 71, per WhoScored.com. Three of the seven names in front of him were Lionel Messi, Neymar and Isco.
Naturally, dribbling, trickery and hard-running form strong components of the Galician's game, but part of what will have appealed to new Real Madrid boss Rafa Benitez is Vazquez's defensive commitment. Last season, the winger was second only to Victor Sanchez for total tackles at Espanyol, and he regularly demonstrated a willingness to track back and support his right-back.
Such a two-way capacity will have played a key role in his return to the Spanish capital, where Marca dubbed him the "the fearless rookie" because of his all-action playing style. The Madrid-based daily also labelled Vazquez "a strategic bargain" and "a pragmatic coup," remarking that he's following "in Callejon's footsteps."
For Real Madrid, the comparison with Callejon is a neat one, given he also spent time at Espanyol before returning to the Bernabeu to be an extremely useful secondary option in attack for Los Blancos. Vazquez, it's hoped, could prove to be something similar, a tireless and aggressive runner who might help shift the essence of this current Real Madrid outfit from precision to power.
Additionally, the club's recalling of a right-sided attacker might represent the clearest indication yet that Gareth Bale will switch to his preferred left wing, with Marca reporting last month that Bale is determined "to throw off the positional yoke" and move away from the right. Should the Welshman be allowed to do so, Benitez will likely position Cristiano Ronaldo at the head of the attack and play the more technical Isco or James Rodriguez down the right.
In that scenario, Vazquez becomes a back-up option of contrast on the right wing, with his preference for hugging the sideline differing from the cut-inside inclinations of Isco and Rodriguez—remember, when looking for secondary options, variety is the ingredient a manager desires.
Additionally, Benitez's expected introduction of substantial rotation throughout the XI should open the door for players such as Vazquez and Jese, the sort of back-up men whose games stagnated under Ancelotti's extremely consistent selection policy.
However, as noted by ESPN FC's Nicholas Rigg, there are some doubts as to whether the buy-back of Vazquez was fuelled by a need to protect Real Madrid against UEFA's homegrown player regulations for the Champions League:
European football's governing body stipulates that clubs must have at least eight players in their 25-man squad who have been at the club for three years between the ages of 15-21, or have been at another club in the same association for that same amount of time.
At the moment, Madrid are fine with 10 players falling under those conditions. However, both Iker Casillas and Sergio Ramos have been linked with moves away from the club this summer and that would reduce the number to eight. Alvaro Arbeloa's future is also up in the air and that leaves Madrid in a dangerous position for the Champions League.
Might concerns over that quota be behind the re-signing of the winger? Perhaps.
But wherever he's gone, Rafa Benitez has shown an eagerness to get hands-on with a club's academy and the talent it has produced, and with a history of working with the youth setup at Real Madrid, the Madrilenian understands the importance of maintaining a connection between the club's various tiers.
Vazquez appears to have benefitted from that. And if he's able to provide Los Blancos with some of what we saw at Espanyol, Real Madrid could benefit too.